Question: If $x \diamond y = x-6y$ and $x \boxdot y = x(y-6)$, find $-1 \boxdot (3 \diamond -3)$.
Explanation: First, find $3 \diamond -3$ $ 3 \diamond -3 = 3-(6)(-3)$ $ \hphantom{3 \diamond -3} = 21$ Now, find $-1 \boxdot 21$ $ -1 \boxdot 21 = -(21-6)$ $ \hphantom{-1 \boxdot 21} = -15$.